SEAT Workshop Service and Repair Manuals > Leon Mk1 > Power unit | Monomotronic injection and ignition system | Mixture preparation system, electronic inj.,Gas | Supplementary signals

Velocity signal: verification

Special tools and workshop equipment required

t	Hand multimeter -V.A.G 1526 A- or multimeter -V.A.G 1715-

t	Fault reader -V.A.G 1551- or vehicle system tester -V.A.G 1552- with cable -V.A.G 1551/3B-

t	Auxiliary measuring set -V.A.G 1594 C-

t	Test box -V.A.G 1598/18-

t	Electric circuits flow diagram

Test conditions

l	Speedometer correct, verification: → Rep. Gr.90

Checking process

Note

To check the speed signal, the vehicle must be driven. To do this a second person is necessary.

–	Connect the equipment -V.A.G 1551- (-V.A.G 1552-). Start engine and select “Address code” 01 to select engine control unit. (Fault reader: Connecting and selecting the engine control unit → Chapter.)

Display indication:

–	Press the keys 0 and 8 for the function “Read measurement block values”, confirm using the key Q.

Rapid data transmission             HELP

Select the function XX

Display indication:

–	Press keys 0, 0 and 4 for “Display group number 4” and confirm entry with Q key.

Read measurement block values       HELP

Input the indication group number XX

Display indication:

(1…4 = Display fields)

–	Carry out a test run, noting the indication in the display (a second operator is required).

–	Note the value displayed in the display field 3:

Read measurement value block         4->

         1         2         3         4

Specification:

0…4 km/h = 0

4…7 km/h = > 4

More than 7 km/h = > 7

–	Press the key →.

–	Press keys 0 and 6 for the “End output” function and confirm input with the Q key.

If no speed is indicated:

–	Switch ignition off.

–	Connect the tester -V.A.G 1598/18- to the control unit cable harness.

–	Set the multimeter to the voltage measurement range and connect it to the sockets 20+36 of the measurement box.

–	Turn the ignition on.

–	Raise the front left hand side wheel.

–	Rotate the front wheel observing the voltage indication.

Specification: oscillating between 0…4 V minimum

SEAT Workshop Service and Repair Manuals